@antv/g2/src/transform/maybeDefaultX.ts

the Grammar of Graphics in Javascript

import { deepMix } from '@antv/util';
import { TransformComponent as TC } from '../runtime';
import { column, isObject } from './utils/helper';

export type MaybeDefaultXOptions = Record<string, never>;

/**
 * Add a default encode for rangeX
 * when data is just an array
 */
export const MaybeDefaultX: TC<MaybeDefaultXOptions> = () => {
  return (I, mark) => {
    const { data } = mark;
    if (
      Array.isArray(data) &&
      (data.every(Array.isArray) || !data.some(isObject))
    ) {
      const extractX = (data, index: number) =>
        Array.isArray(data[0])
          ? data.map((item) => item[index])
          : [data[index]];
      return [
        I,
        deepMix({}, mark, {
          encode: {
            x: column(extractX(data, 0)),
            x1: column(extractX(data, 1)),
          },
        }),
      ];
    }
    return [I, mark];
  };
};

MaybeDefaultX.props = {};